Reclining vehicle seat hinge assemblies are well known in the art, and typically include pawls with a plurality of teeth that releasably engage a circular set of teeth in a housing attached to the seat. Upon movement of a lever, the pawl teeth are released from engagement with the housing teeth, allowing the user to pivot the seat back to a desired position. When the desired position is reached, the lever is released and the pawl teeth engage the housing teeth, locking the seat back at the desired position. Many known reclining vehicle seat hinge assemblies include a pair of pawls with teeth that engage the housing teeth. Such assemblies with just a pair of pawls must have a substantial thickness in order to provide the strength required to absorb the impact forces that result when the vehicle is involved in a collision.
U.S. Pat. No. 6,561,585 to Cilliere et al. discloses a vehicle seat hinge assembly having a first pair of pawls, or locking slugs, that engage housing teeth and act to lock the seat back in the desired position. A second pair of blocking slugs with side surfaces having dihedral angles is positioned such that they allow some play in the circumferential direction. In normal use, the blocking slugs produce no effect. Upon an impact, the blocking slugs deform the guides along which they travel so as to pivot and wedge into an interfering fit with the teeth of the housing, helping to absorb the impact forces. Cilliere is limiting in that its four pawl construction is quite complex, which leads to increased manufacturing costs. Further, Cilliere's inertially operated mechanism requires the shape of the blocking slugs and associated components to be manufactured to close tolerances in order to operate in the designed manner, further contributing to increased manufacturing costs and complexity of design.
It is an object of the present invention to provide a reclining vehicle seat hinge assembly that reduces or overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments.